The present invention relates to a thin-film electroluminescent (referred to as "EL") display panel and, more particularily, to a thin-film EL display unit shielded by a pair of glass substrates from which moisture is completely removed, and the fabrication method.
There was filed on June 14, 1978 a U.S. patent application Ser. No. 915,447 by M. Kawaguchi et al entitled "THIN-FILM ELECTROLUMINESCENT DISPLAY PANEL SEALED BY GLASS SUBSTRATES AND FABRICATION METHOD THEREOF", now U.S. Pat. No. 4,213,074, assigned to the present assignee. The counterpart application was filed in England on July 31, 1978 as British patent application No. 31666/78 and in West German on July 25, 1978 as W. German patent application No. P 28 32 652.5.
In terms of a seal of an EL display panel by a pair of glass substrates including a protective liquid such as silicone oil or grease as disclosed in the above referred to applications, the introduction of moisture into a cavity defined by the pair of glass substrates from the surroundings was prevented to thereby increase the reliability and the life time of the EL display panel.
However, there were inherent disadvantages, owing to the fact that the protective liquid inevitably contains a small amount of moisture, such that the small amount of moisture inclusive in the protective liquid tended to penetrate into the EL display film, thus damaging the EL display unit.